as above.
more info is needed
what phone is it?
what operating system on the pc?
samsung strasosphere, Windows XP
once you plug in the phone via usb select mass storage
okay did that
having the same problem. Droid2. Connected phone to PC with USB cable. Used to work fine, but now the phone is not even being discovered as a device.
Have you verify that all drivers are loaded in the Service Manager?